KR950002238B1 - Crystal of fluoran compound, preparation process of the crystal and recording material comprising the crystal - Google Patents

Abstract

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Description

Crystals of Fluorane Compounds, Methods of Making the Crystals, and Recording Materials Containing the Crystals

1 is an X-ray diffraction diagram of Form I-a crystals of the fluorane compound represented by Formula (I) of the present invention.

2 is an X-ray diffraction diagram of a well-known Form I-b crystal of the fluorane compound represented by Formula (I).

3 is an X-ray diffraction diagram of a II-a crystal of the fluorane compound represented by formula (II) of the present invention.

4 is an X-ray diffraction diagram of a known II-b crystal of the fluorane compound represented by formula (II).

In each figure, the horizontal axis represents the diffraction angle 2θ, and the vertical axis represents the diffraction intensity.

Fig. 5 shows the color density characteristics with respect to temperature in the thermal recording paper prepared by using the type I-a crystals of the present invention and known type I-b crystals, respectively.

In the figure, curve (a) shows type I-a crystals, and curve (b) shows color development density characteristics of type I-b crystals, respectively.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorane compound useful as a chromogenic compound used in recording materials such as a reduced pressure recording material and a thermal recording material, and more particularly, a crystal of a fluorane compound, an isolation method thereof, and a recording containing the crystal. It is about the material.

Conventionally, a color reaction between a colorless or pale electron donating compound (chromic compound) and an organic or inorganic electron-accepting substance (developing agent) is used, and information transmitted by mediation of external energy such as pressure, heat or electricity is recorded. Examples of the method include decompression recording, thermal recording, and energizing thermal recording.

In these recording methods, fluorane compounds are widely used as chromogenic compounds.

Formula I

Fluorane compounds represented by the above are compounds which are recorded as color-developing compounds in Japanese Patent Laid-Open Nos. 59-65053, 60-47066 and 60-141762, but the formulas (I) described in these publications The fluorane compounds represented by the above all have a melting point of about 180 ° C. (see Japanese Patent Application Laid-Open Nos. 59-65053; 181.2-182.6 ° C, Japanese Patent Laid-Open No. 60-47066; 177-178 ° C, and Japanese Patent Laid-Open No. 60-141762). Publication 178-180 ° C).

Crystals of the fluorane compound of formula (I) having this melting point are difficult to finely pulverize, have a long time to finely granulate, and are difficult to control dispersions of chromogenic compounds for thermal recording materials. There was.

In addition, when the crystal of the fluorane compound of formula (I) having this melting point is used as a recording material, for example, a color developing compound for a thermosensitive recording material containing bisphenol A as a color developer, the color development temperature is high, but high-speed recording is desired. It is difficult to say that there are currently chromophoric compounds having a sufficiently satisfactory performance. Although the fluorane compound represented by Formula (II) is disclosed as a general formula in Unexamined-Japanese-Patent No. 54-34909, the physical property value about this compound is not disclosed at all.

Further, Japanese Patent Application Laid-Open No. 60-35053 discloses a fluorane compound of formula (II).

The crystals of the fluorane compound of formula (II) prepared in the manner described in Japanese Patent Application Laid-Open No. 60-35053 also have disadvantages that they are difficult to finely grind and require a long time to become particulates. There was a problem that it was difficult to prepare a dispersion.

Moreover, the crystal | crystallization of the fluorane compound represented by Formula (II) isolate | separated by the method of Unexamined-Japanese-Patent No. 60-35053 has the drawback that it is unstable with light and yellows quickly by light irradiation. For this reason, when this crystal is used, for example, as a color developing compound for thermal recording paper, there is a drawback that the uncolored part (paper surface) of the paper is yellowed by light irradiation, and there is a big problem in practical use.

SUMMARY OF THE INVENTION An object of the present invention is to improve the drawbacks of the fluorane compounds represented by the formulas (I) and (II) as color developing compounds for recording materials and to provide excellent characteristics for pressure-sensitive and thermal recording materials, especially for thermal recording materials. The present invention provides crystals of the fluorane compounds represented by the novel crystalline forms (I) and (II).

MEANS TO SOLVE THE PROBLEM The present inventors earnestly examined about the fluorane compound of Formula (I) and (II) so that the said fault may be improved, As a result, the crystalline form conventionally known for the fluorane compound of Formula (I) and Formula (II) is known. The present invention was completed by finding out that there are new crystalline forms different from those of the present invention, and having excellent performance as crystals of fluorane compounds of these new crystalline forms, reduced pressure, and color developing compounds for thermal recording materials.

That is, in the X-ray diffraction method using Cu-Kα rays, X exhibits strong peaks at diffraction angles (2θ) of 7.5 ° and 17.0 °, and relatively strong peaks at 15.1 °, 19.1 °, 21.5 ° and 25.3 °. Equation (Ⅰ) Characterized by the Diffractogram of a Line

In the X-ray diffraction method using the crystal of the fluorane compound represented by the formula and Cu-Kα rays, the formula (II) characterized by the X-ray diffractogram showing peaks at 5.5 ° and 19.2 ° of diffraction angle (2θ). It is a fluorane compound crystal shown.

Moreover, it is a method of producing this crystal and a recording material containing the crystal.

Crystals having a novel crystalline form of the fluorane compounds represented by the formulas (I) and (II) of the present invention have excellent performance as color-developing compounds for recording materials as compared to conventionally known crystal forms.

The fluorane compound of formula (I) is a benzoic acid derivative of formula (III) and the diphenylamine derivative of general formula (IV). The fluorane compound of formula (II) is a benzoic acid derivative of formula (V), and Diphenylamine derivative of IV),

(Wherein R represents a lower alkyl group having 1 to 4 carbon atoms)

For example, in the presence of dehydrating condensing agents such as concentrated sulfuric acid, fumed sulfuric acid, concentrated sulfuric acid, polyphosphoric acid, phosphorus pentaoxide, aluminum anhydride, and the like, particularly preferably, after reaction in concentrated sulfuric acid, alkalizing is produced.

Dehydration condensation reaction is normally performed at the reaction temperature of 0-100 degreeC for several hours-100 hours.

The reaction temperature is particularly preferably a temperature of 0 to 50 ° C. when the reaction is carried out especially in concentrated sulfuric acid. The reaction time depends on the reaction temperature so that sufficient time is allowed to react. In the alkali treatment usually carried out after dehydration condensation, the pH is set to 9 to 12 with potassium hydroxide water, sodium hydroxide water and the like, and is preferably carried out at a temperature range of 0 to 100 ° C. At this time, alkali treatment may be performed in the presence of organic solvents such as benzene and toluene other than water.

The crystal of the fluorane compound of the present invention relates to a novel crystalline form of the fluorane compound represented by the formulas (I) and (II) produced by the above reaction.

First, the crystal | crystallization of the fluorane compound represented by Formula (I) of this invention is demonstrated in detail.

The crystal of the fluorane compound represented by the formula (I) of the present invention is an organic solvent solution containing 30% by weight of an aromatic hydrocarbon solvent containing the fluorane compound represented by the formula (I) obtained by the above reaction, This compound can be prepared by precipitation as a crystal and then isolation.

Preferable specific examples of the aromatic hydrocarbon solvent include benzene, toluene, xylene, ethylbenzene, chlorobenzene or dichlorobenzene. These solvents can be used individually or in mixture.

The aromatic hydrocarbon solvent may be any other organic solvent such as alcohol solvents such as methanol, ethanol, propanol, butanol, ketone solvents such as acetone and methyl ether ketone, ether solvents such as tetrahydrofuran and dioxane, It can also be used as a mixed solution with polar solvents such as acetonitrile and dimethylformamide.

When using an aromatic hydrocarbon solvent as a mixed solution with other organic solvents, for example, in a mixed solution composed of 20% by weight of toluene and 80% by weight of methanol, the crystal of the fluorane compound represented by formula (I) is precipitated. Another crystalline form (form I-b described later) is precipitated. In preparing the crystal of the present invention, the content of the aromatic hydrocarbon solvent in the mixed solution is preferably 30% by weight or more, more preferably 40% by weight or more.

As for the usage-amount of the organic solvent which contains 30 weight% or more of aromatic hydrocarbon solvents, about 0.4 weight times or more are preferable with respect to the weight of the fluorane compound represented by Formula (I). When too few, the fluorane compound represented by Formula (I) is not a crystal | crystallization, and may produce | generate as amorphous. On the other hand, even if a large amount of this solvent is used, there is no particular problem, but it is not preferable from the viewpoint of economical efficiency or the necessity of operation such as concentration in order to precipitate crystals. The amount of the solvent used is usually about 0.4 to 100 weight times, more preferably about 0.5 to 50 weight times, based on the weight of the fluorane compound represented by the formula (I).

As a method of precipitating the crystal, a method of precipitating the fluorane compound completely in a solvent and then cooling precipitation is frequently used. Under the present circumstances, you may heat in the range of the boiling point of a solvent more than room temperature as needed, and may completely dissolve a fluorane compound. After complete dissolution, crystals are precipitated under stirring or standing.

In the preparation of the fluorane compound represented by formula (I), an aromatic hydrocarbon solvent coexists in the alkali treatment step after the dehydration and condensation reaction, and is represented by formula (I) dissolved in the solvent after alkali treatment. Even if the fluorane compound is precipitated as a crystal, the crystal of the fluorane compound represented by the formula (I) of the present invention can be produced.

The precipitated crystals do not need to be isolated by a special method, but can be obtained by a known method such as, after being filtered, dried to a temperature below the melting point, to obtain crystals of the fluorane compound represented by the formula (I) of the present invention. .

Crystals of the fluorane compound represented by the formula (I) of the present invention produced by the above-described method are strong in diffraction angles (2θ) 7.5 ° and 17.0 ° in the X-ray diffraction method using Cu-Kα rays, X-ray diffractograms (shown in FIG. 1) giving relatively strong peaks at 15.1 °, 19.1 °, 21.5 ° and 25.3 ° are given (hereinafter, this crystal is referred to as I-a blood crystal). In addition, crystals precipitated in a fluorane compound of formula (I), such as an isopropanol solvent, prepared by a known method, exhibit strong peaks at 8.7 ° and 14.7 ° at a diffraction angle (1θ) of 15.7 °, 19.1, as shown in FIG. Relatively strong peaks are shown at °, 20.1 °, 21.4 ° and 22.9 ° (hereinafter, this crystal is referred to as I-b type crystal).

(In addition, an error of about ± 0.2 degrees is allowed in the display of the diffraction angle.)

As is apparent from the X-ray diffraction diagrams of FIGS. 1 and 2, the crystal of Form I-a of the present invention is a crystal form different from the known Form I-b crystal.

Moreover, melting | fusing point of the I-b type | mold crystal of this invention is 162-164 degreeC, and differs greatly by melting | fusing point (181-183 degreeC) of a well-known I-b type | mold crystal | crystallization.

The crystal of Form I-a of the present invention can also be produced from known Form I-b crystals.

That is, the crystal of type I-a can be dissolved in an organic solvent containing 30% by weight or more of an aromatic hydrocarbon solvent, precipitated with crystals, and isolated.

Specifically, I-b crystals are dissolved in, for example, aromatic hydrocarbon solvents (benzene, toluene, xylene, ethylbenzene, chlorobenzene or dichlorobenzene or a mixed solvent thereof) at room temperature to the boiling point of the solvent, followed by precipitation. The crystal of Form I-a of the present invention can be prepared by drying a crystal in a known manner, such as after filtration.

When the compound represented by the formula (I) is determined from a solution of an isopropanol solvent (described in Japanese Patent Application Laid-Open Nos. 59-65053 and 60-47066) or an acetonitrile solvent, precipitation of Form I-b crystals is obtained. By changing the solvent into an organic solvent containing 30% by weight or more of an aromatic hydrocarbon solvent, the fact that the crystal of Form I-a of the present invention, which is not known in the prior art, can be produced is an unexpected wonder.

Next, the crystal | crystallization of the fluorane compound represented by Formula (II) of this invention is demonstrated.

Crystals of the fluorane compound represented by formula (II) of the present invention can be obtained from a solution of an organic solvent containing 50% by weight or more of an alcohol solvent having 3 to 18 carbon atoms containing the fluorane compound represented by formula (II). After the compound is precipitated as crystals, it can be isolated and obtained.

When the crystal of the fluorane compound represented by formula (II) is precipitated from a solution of methanol or ethanol solvent which is an alcohol having 2 or less carbon atoms, the crystal obtained is another crystal form different from the crystal of the present invention (Form II-b which will be described later). And an alcohol having 2 or less carbon atoms is not preferable as an organic solvent for depositing crystals of the fluorane compound of formula (II) of the present invention.

Although an alcohol solvent having 3 or more carbon atoms is preferably used as an organic solvent for precipitating crystals of the fluorane compound of formula (II) of the present invention, an alcohol solvent having a high carbon number is difficult to obtain, or has a high boiling point. In general, a C3-C18 alcohol solvent is preferable, and a C3-C18 aliphatic alcohol solvent is more preferable because handling becomes difficult.

Specific examples of the alcohol solvent having 3 to 18 carbon atoms include propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, penta And aliphatic alcohols such as decanol, hexadecanol, heptadecanol, and octadecanol. These solvents can be used individually or in mixture. In particular, when used alone, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, and dodecanol are preferable.

In addition, alcohol solvents having 3 to 18 carbon atoms and other organic solvents such as methanol and ethanol; Ketone solvents such as acetone and methyl ethyl ketone; Ester solvents such as ethyl acetate and butyl acetate; Ether solvents such as tetrahydrofuran and dioxane; Polar solvents such as acetonitrile and dimethylformamide; Although mixed solvents with aromatic hydrocarbon solvents such as benzene, toluene, xylene, chlorobenzene and the like can be used, if the ratio of the alcohol solvent having 3 to 18 carbon atoms in the mixed solvent is very small, crystals of another crystalline form (described later in II) -b type crystals) may be precipitated, so that the proportion of the alcohol solvent having 3 to 18 carbon atoms in the mixed solvent is usually preferably 50% by weight or more, and more preferably 80% by weight or more.

In addition, when the usage-amount of the organic solvent containing 50 weight% or more of C3-C18 alcohol solvents is too small, the fluorane compound of Formula (II) may be produced as an amorphous (amorphous), not a crystal | crystallization. Therefore, about 0.4 weight or more is preferable with respect to the weight of the fluorane compound of Formula (II).

Although it does not have a problem even if it uses a large amount of this solvent, it is not preferable from an economical viewpoint or in order to carry out operations, such as concentration, in order to precipitate a crystal | crystallization. The amount of the solvent used is usually about 0.4 to 100 times by weight, more preferably about 0.5 to 50 times by weight, based on the weight of the fluorane compound represented by the formula (II).

As a method of precipitating the crystal, a method of precipitating the fluorane compound completely in a solvent and then cooling precipitation is frequently used. Under the present circumstances, you may heat in the range of the boiling point of a solvent above room temperature as needed, and may fully melt | dissolve a fluorane compound. After complete dissolution, crystals are precipitated under stirring or standing. Isolation of the precipitated crystals can be carried out by a known method, for example, by filtration, drying at a temperature not higher than the melting point, and obtaining a crystal of the fluorane compound of formula (II) of the present invention.

Crystals of the fluorane compound represented by the formula (II) of the present invention isolated by the following method exhibit strong peaks at 5.5 ° and 19.2 ° of diffraction angle (2θ) in the X-ray diffraction method using Cu-Kα rays. An X-ray diffractogram (FIG. 3) is provided (hereinafter, this crystal is called a II-a crystal).

On the other hand, the crystal of the fluorane compound represented by the method of Japanese Patent Application Laid-Open No. 60-35053 (precipitated crystals from toluene) or formula (II) isolated in methanol or ethanol solution has a diffraction angle ( 2θ) Gives strong peaks at 7.7 °, 13.1 °, 17.4 °, 20.3 ° and 20.5 ° (hereinafter, this crystal is referred to as type II-b crystal).

(In addition, an error of about ± 0.2 ° is allowed in the display of the diffraction angle.)

As is apparent from the X-ray diffraction diagrams of FIGS. 3 and 4, the type II-a crystal of the present invention is different from the known type II-b crystal.

The melting point of the type II-a crystal of the present invention is 168 to 171 ° C, and the melting point of the known type II-b crystal is significantly different from that of 136 to 141 ° C.

The II-a crystal of the present invention can also be produced from known II-b crystals. That is, the II-b crystals can be dissolved in an organic solvent containing 50% by weight or more of an alcohol solvent having 3 to 18 carbon atoms, and then precipitated and isolated as crystals.

Specifically, the type II-b crystals are, for example, propanol, butanol, pentanol, hexanol, heptanol, octanol, nananol, decanol, undecanol or dodecanol, or a mixed solvent thereof, at room temperature to the boiling point of the solvent. After dissolving at a temperature range of, the precipitated crystals can be prepared by a known method, such as filtration, followed by drying, to thereby prepare the II-b crystals of the present invention.

When the fluorane compound of formula (II) is precipitated as crystals in a toluene solvent (described in Japanese Patent Application Laid-Open No. 60-35053) or in a solution of acetonitrile or a methanol or ethanol solvent having an alcohol solvent of 2 or less carbon atoms, it is a type II-b. Although crystals are prepared, by changing the solvent to a solvent containing 50% by weight or more of an alcoholic solvent having 3 to 18 carbon atoms, the fact that the II-a crystals of the present invention, which have not been known in the art, can be produced is not expected at all. This is a wonderful fact.

Form I-a crystals of the fluorane compound represented by formula (I) of the present invention prepared as described above and type II-a crystals of the fluorane compound represented by formula (II) of the present invention are variously recorded as chromogenic compounds. Can be used for materials.

In this case, they may be used alone or in combination.

In addition, for example, in order to adjust the color of color development, other color-developing compounds, such as triphenyl methane lactones, fluoranes, spiropyranes, etc., may be mixed and used as desired.

The recording material of the present invention is a reduced pressure or thermally sensitive recording material containing the I-a type crystal and the II-a type crystal of the present invention.

When the crystal of the fluorane compound of the present invention is used, for example, as a pressure-sensitive recording material, it is a solvent commonly used in this field, for example, an alkylbenzene system (such as n-dodecylbenzene), an alkylbiphenyl system (trimethylbiphenyl, di Isopropyldiphenyl, etc.), hydrogenated taphenyl series, alkylnaphthalene series (diisopropyl naphthalene, etc.), diarylethane series (phenylxylethane, ethyl styrene benzene, etc.), or chlorinated paraffinic solvents alone or mixed. It is dissolved in a solvent, and the solution is sealed in a microcapsule having partitions of gelatin, melamine-aldehyde, urea-aldehyde resin, polyurethane, polyurea and polyamide by methods such as core selvation and interfacial polymerization. The aqueous dispersion of the obtained capsule is applied with a suitable binder (e.g., starch paste, latex, etc.) onto a suitable support (e.g., paper, plastic sheet, resin coated paper, etc.) A recording sheet and the like can be used.

Of course, the above-mentioned capsular dispersion is applied to one side of the support, and the so-called middle sheet, which is applied to the opposite side, is mainly coated with a developer, and the coating solution in which the capcel and the developer are mixed on the same side of the support. Alternatively, a coating agent coating solution may be applied onto the capsule dispersion solution, and the like can be used for a so-called single copy sheet or the like in which the capsule and the developer are coexisted on the same surface.

In this case, as the developer, a salicylic acid, a copolymer of phenols and aldehydes (e.g., formaldehyde), a substituted salicylic acid (alkyl substituted, aryl substituted or aralkyl substituent, such as extremely well known 3, 5-di-α- Methylbenzyl salicylic acid), co-condensation of substituted salicylic acid with styrene, alkylphenols (e.g. octylphenol), phenol-aldehyde resins (e.g. novolac resins of p-phenylphenol) or metal salts thereof, e.g. zinc And metal salts such as magnesium, aluminum, calcium, tin, and nickel, and furthermore, active clay.

In addition, when used in the thermal recording material, the crystal and developer of the fluorane compound of the present invention (for example, bisphenol A or its halide or alkylate, dihydroxydiphenylsulfone or its halide or alkylate, hydroxybenzoic acid) Esters, phenols such as hydroquinone monoesters, organic colorants such as salicylic acid derivatives, salicylic acid amide derivatives, urea derivatives, thiourea derivatives or inorganic solvents such as acidic clay, attapulgite, activated clay, aluminum chloride, zinc embrittlement Binder (e.g., polyvinyl alcohol or its modified product, methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, gum arabic, styrene-maleic anhydride copolymer, etc.) , Pigments (talc, kaolin, calcium carbonate, etc.) and sensitizers (higher fatty acid amides, aromatic carboxylic acids, or sulfones, if necessary). General well-known sensitizers for thermal recording materials such as acid esters, aromatic to aromatic group substituted aliphatic ethers, or aromatic to aromatic group substituted aliphatic hydrocarbons, and other additives (for example, ultraviolet absorbers, antifoaming agents, etc.) It can be used as a dispersion, coated on a suitable support (for example, paper, plastic sheet, paper coated with resin, etc.) and used as a thermal recording material. Of course, it is not a water dispersion system, but can use it without a problem also in the system using a solvent. Moreover, it can also be used for the use (for example, Zion material) which uses other chromogenic compounds.

Type I-a crystals of the fluorane compound represented by Formula (I) of the present invention and type II-a crystals of the fluorane compound represented by Formula (II) are fluorane compounds represented by well-known Formula (I). In comparison with the I-b crystals of Formula 1 and the II-b crystals of the fluorane compound represented by Formula (II), the particles are more easily formed, and in a short time, especially when preparing a coating solution of a chromogenic compound for thermal recording materials. It is a crystal that can be formulated and has industrially exceptional advantages. That is, 10 g of 2 wt% polyvinyl alcohol and 60 g of glass beads having a diameter of 1 g of the I-a crystals, the II-a crystals, the known I-b crystals and the II-b crystals of the present invention were respectively The sand grinder was used to compare the time taken for each crystal to have an average particle diameter of 1.5 µm.

The results are shown in Table 1.

TABLE 1

As is clear from Table 1, the crystals of Form I-a and Form II-a of the present invention can be micronized in about 1/2 of the time compared to known Form I-b and Form II-b crystals. Able to know.

A thermosensitive recording paper prepared by using the present invention type I-a crystal of the fluorane compound represented by formula (I) as a color developing compound for a recording material, for example, a thermosensitive recording material, and using, for example, bisphenol A as a developer. The color develops faster at a lower temperature as compared to the thermal recording paper prepared using a well-known type I-b crystal (FIG. 5).

From this fact, it is possible to say that at present, the high-speed recording of thermal recording paper is strongly requested, the type I-a crystal of the present invention is a chromic compound having excellent performance.

In addition, the uncolored part (surface) of the thermal recording paper prepared by using the fluorine compound represented by the formula (II), the crystal of the present invention type II-a as a color developing compound, and using bisphenol A as the developer. Its light resistance is superior to that of thermal recording paper using II-b crystals. That is, the uncolored portion of the thermal recording paper using the II-a type crystal of the present invention and the thermal recording paper using the II-b type crystal was irradiated with sunlight for 3 hours, and the light resistance was investigated.

The results are shown in Table 2.

TABLE 2

○ in the table represents paper with high whiteness.

× represents yellowed paper.

Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to an Example.

Example 1

[Preparation of Form I-a Crystal of the Present Invention]

94 g of 2- (4'-Nn-butyl-N-ethylamino-2'-hydroxybenzoic acid) benzoic acid [compound of formula (III)] was dissolved in 550 g of concentrated sulfuric acid at 10 to 15 ° C., followed by 4-methoxy 59 g of 2-methyldiphenylamine [compound whose R is a methyl group in general formula (IV)] are added at the same temperature, and it stirred at 10-15 degreeC for 24 hours. The reaction mixture was discharged into 3000 ml of ice water, the precipitated solids were collected and washed, the solid was added to a 10% aqueous NaOH solution (1000 ml), and again 1000 ml of toluene was added, followed by stirring at 60 to 70 ° C for 2 hours. After the toluene layer was separated and washed with warm water until neutral, the toluene layer was separated, 800 ml of toluene was distilled off at 40 ° C under reduced pressure, and then allowed to stand at room temperature. Precipitated crystals were filtered off, washed with a small amount of toluene, washed with methanol again, and dried at 60 ° C. for 24 hours to give 125 g of an almost colorless crystal.

Melting Point 162 ~ 164 ℃

The powder X-ray diffractogram is shown in FIG.

Example 2

[Preparation of Form I-a Crystal of the Present Invention]

After dissolving 94 g of 2- (4'-Nn-butyl-N-ethylamino-2'-hydroxybenzoyl) benzoic acid in 550 g of concentrated sulfuric acid at 10 to 15 캜, 59 g of 4-methoxy-2-methyldiphenylamine Was added at the same temperature, and stirred at 10 to 15 ° C for 24 hours. The reaction mixture was discharged into 3000 ml of ice water, and the precipitated solids were collected and washed. The solid was added to a 10% aqueous NaOH solution (1000 ml), and 1000 ml of toluene was further added, followed by stirring at 60 to 70 ° C for 2 hours. The toluene layer was separated, washed until warmed in warm water, the toluene layer was separated, the toluene was distilled off at 40 ° C under reduced pressure, and then toluene (200 g) and methanol (300 g) were added to the sticky oil of the residue. It was left to stand at room temperature. Precipitated crystals are filtered off, washed with methanol, dried at 60 ° C for 24 hours, and 130 g of a colorless crystal is obtained.

Melting Point 162 ~ 164 ℃

This gave the X-ray diffraction figure shown in FIG.

Example 3

[Production of Form I-a Crystal of the Invention]

Crystals were obtained according to the method described in Example 1 except that benzene was used instead of toluene in Example 1.

Melting Point 162 ~ 164 ℃

This gave the X-ray diffractogram as shown in FIG.

Example 4

[Preparation of Form I-a Crystal of the Present Invention]

Crystals were obtained in accordance with the method described in Example 1 except that mixed xylene was used instead of toluene in Example 1.

Melting Point 162 ~ 164 ℃

This gave the X-ray diffractogram as shown in FIG.

Example 5

[Preparation of Form I-a Crystal of the Present Invention]

Crystals were obtained in accordance with the method described in Example 1 except that ethylbenzene was used instead of toluene in Example 1.

Melting Point 162 ~ 164 ℃

This gave the X-ray diffractogram as shown in FIG.

Example 6

[Preparation of Form I-a Crystal of the Present Invention]

A crystal was obtained according to the method described in Example 1 except that chlorobenzene was used instead of toluene in Example 1.

Melting Point 162 ~ 164 ℃

This gave the X-ray diffractogram as shown in FIG.

Reference Example 1

[Production of Known Form I-b Crystals]

9.4 g of 2- (4'-Nn-butyl-N-ethylamino-2'-hydroxybenzoyl) benzoic acid was dissolved in 55 g of concentrated sulfuric acid at 10 to 15 캜, followed by 4-methoxy-2-methyldiphenylamine 5.9 g is added at the same temperature and stirred at 10-15 ° C. for 24 hours. The reaction mixture was discharged into 3000 ml of ice water, and the precipitated solids were collected, washed, added to 100 ml of 10% NaOH aqueous solution, and stirred at 60 to 70 ° C for 2 hours. The solid is filtered off, washed and dried. This is recrystallized again in 300 ml of isopropanol to give a nearly colorless crystal 12.

Melting Point 181 ~ 183 ℃

Powder X-ray diffraction is shown in FIG.

Reference Example 2

[Production of Known Form I-b Crystals]

Crystals were obtained in accordance with the method described in Reference Example 1 except that acetonitrile was used instead of isopropanol in Reference Example 1.

Melting Point 181 ~ 183 ℃

This gave the X-ray diffractogram as shown in FIG.

Reference Example 3

[Production of Known Form I-b Crystals]

In Example 2, crystals were obtained according to the method described in Example 2 except that 200 g of toluene and 300 g of methanol were added instead of 100 g of toluene and 400 g of methanol. This is a type I-b crystal.

Melting Point 181 ~ 183 ℃

This gave the X-ray diffractogram as shown in FIG.

Example 7

[Preparation of Form I-a Crystals from Form I-b Crystals]

10 g of Form I-b crystals are dissolved by heating to 30 ml of toluene, cooled to room temperature and left to stand. The precipitated crystals are filtered off and dried at 60 ° C. for 24 hours to obtain crystals that are almost colorless.

Melting Point 162 ~ 164 ℃

This gave the X-ray diffractogram as shown in FIG.

Example 8

[Preparation of Form I-a Crystals from Form I-b Crystals]

Crystals were obtained in accordance with the method described in Example 7 except that mixed xylene was used instead of toluene in Example 7.

Melting Point 162 ~ 164 ℃

This gave the X-ray diffractogram as shown in FIG.

Example 9

[Preparation of Form I-a Crystals from Form I-b Crystals]

According to the method described in Example 7, except for using chlorobenzene instead of toluene in Example 7, crystals were obtained.

Melting Point 162 ~ 164 ℃

This gave the X-ray diffractogram as shown in FIG.

Example 10

[Preparation of Form I-a Crystals from Form I-b Crystals]

Crystals were obtained in accordance with the method described in Example 7 except that o-chlorobenzene was used instead of toluene in Example 7.

Melting Point 162 ~ 164 ℃

This gave the X-ray diffractogram as shown in FIG.

Example 11

[Preparation of Form II-a Crystals of the Present Invention]

100 g of 2- (4'-N-cyclohexyl-Nn-aluminoamino-2'-hydroxybenzoyl) benzoic acid [compound of formula (V)] was dissolved in 460 g of 98% sulfuric acid at 10 to 15 ° C., and then 4- 53 g of methoxy-2-methyldiphenylamine are added at the same temperature and stirred at 10 to 15 ° C for 24 hours. The reaction mixture is discharged into 3000 ml of ice water, the precipitated solids are collected and washed, the solid is added to 1000 ml of 10% aqueous NaOH solution, and 1000 ml of toluene is added again, followed by stirring at 60 to 70 ° C for 2 hours. After separating the toluene layer, washing it with warm water until neutral, separating the toluene layer, distilling off the toluene at 40 ° C under reduced pressure, adding 300 ml of isopropanol to the residue oil, and stirring at 60 ° C for 1 hour. The mixture was cooled to room temperature, and the precipitated crystals were filtered, washed with isopropanol, and dried at 60 ° C. for 24 hours to obtain 110 g of almost colorless crystals.

Melting Point 168 ~ 171 ℃

Powder X-ray diffraction is shown in FIG.

Example 12

[Preparation of Form II-a Crystals of the Present Invention]

Crystals were obtained according to the method described in Example 11 except that n-butanol was used instead of isopropanol in Example 11.

Melting Point 168 ~ 171 ℃

This gave the X-ray diffractogram as shown in FIG.

Example 13

[Preparation of Form II-a Crystals of the Present Invention]

Crystals were obtained according to the method described in Example 11 except that n-pentanol was used instead of isopropanol in Example 11.

Melting Point 168 ~ 171 ℃

This gave the X-ray diffractogram as shown in FIG.

Example 14

[Preparation of Form II-a Crystals of the Present Invention]

Crystals were obtained according to the method described in Example 11 except that n-hexanol was used instead of isopropanol in Example 11.

Melting Point 168 ~ 171 ℃

This gave the X-ray diffractogram as shown in FIG.

Example 15

[Preparation of Form II-a Crystals of the Present Invention]

Crystals were obtained according to the method described in Example 11 except that n-octanol was used instead of isopropanol in Example 11.

Melting Point 168 ~ 171 ℃

This gave the X-ray diffractogram as shown in FIG.

Example 16

[Preparation of Form II-a Crystals of the Present Invention]

Crystals were obtained according to the method described in Example 11 except that n-decanol was used instead of isopropanol in Example 11.

Melting Point 168 ~ 171 ℃

This gave the X-ray diffractogram as shown in FIG.

Example 17

[Preparation of Form II-a Crystals of the Present Invention]

In Example 11, a crystal was obtained according to the method described in Example 11 except that a mixed solvent of isopropanol (250 g) and toluene (50 g) was used instead of isopropanol.

Melting Point 168 ~ 171 ℃

This gave the X-ray diffractogram as shown in FIG.

Reference Example 4

[Production of Form II-b Crystals by the Method of Japanese Patent Application Laid-Open No. 60-35053]

12.3 g of 2- (4'-N-cyclohexyl-Nn-amylamino-2'-hydroxybenzoyl) benzoic acid was dissolved in 100 g of 98% sulfuric acid at 20 DEG C, and 4-methoxy-2 at 0-5 DEG C. 7.1 g of methyldiphenylamine is added, and the reaction is carried out at the same temperature for 2 hours, at 20 to 30 ° C for 24 hours and again for 40 hours. After adding the reaction mixture in 500 ml of ice water, 10% aqueous NaOH solution was added, the pH was 7-8, and the precipitate was filtered and collected. 400 ml of toluene and 200 ml of 10% NaOH aqueous solution were added to the cake, and after stirring for 2 hours under reflux, the toluene layer was separated, washed again, concentrated, and the precipitated crystals were collected by filtration and dried again. To obtain.

Melting Point 136 ~ 141 ℃

Powder X-ray diffraction is shown in FIG.

Reference Example 5

[Production of Form II-b Crystals]

33 g of 2- (4'-N-cyclohexyl-Nn-aluminoamino-2'-hydroxybenzoyl) benzoic acid was dissolved in 150 g of 98% sulfuric acid at 10 to 15 DEG C, followed by 4-methoxy-2-methyldiphenyl 17.5 g of amine are added, added at the same temperature, and stirred at 10-15 ° C. for 24 hours. The reaction mixture was discharged into 1000 ml of ice water, and the precipitated solids were collected, washed, and the solids were added to 300 ml of a 10% NaOH aqueous solution, and 330 ml of toluene was further added, followed by stirring at 60 to 70 ° C for 2 hours. After the toluene layer was separated, the toluene layer was separated after washing until warmed in warm water, and the toluene was distilled off and removed at 40 ° C under reduced pressure. 200 ml of methanol was added to the viscous oil of the residue, and the precipitated crystals were filtered, washed with a small amount of methanol, dried at 60 ° C for 24 hours, and 28 g of light brown crystals were obtained.

Melting Point 136 ~ 141 ℃

This gave the X-ray diffraction figure shown in FIG.

Reference Example 6

[Production of Form II-b Crystals]

27 g of crystals were obtained by the method described in Reference Example 5 except that ethanol was used instead of methanol in Reference Example 5.

Melting Point 136 ~ 141 ℃

This gave an X-ray diffractogram as shown in FIG.

Reference Example 7

[Production of Form II-b Crystals]

27 g of crystals were obtained by the method described in Reference Example 5 except that acetonitrile was used instead of methanol in Reference Example 5.

Melting Point 136 ~ 141 ℃

This gave an X-ray diffractogram as shown in FIG.

Example 18

[Preparation of Form II-a Crystals from Form II-b Crystals]

10 g of Form II-b crystals are dissolved in 150 ml of isopropanol by heating, and after cooling to room temperature, the precipitated crystals are filtered and dried at 60 ° C. for 24 hours to obtain 9 g of almost colorless crystals.

Melting Point 168 ~ 171 ℃

This gave the X-ray diffraction diagram as shown in FIG.

Example 19

[Preparation of Form II-a Crystals from Form II-b Crystals]

After dissolving 10 g of II-b crystals in 80 ml of n-butanol and cooling to room temperature, the precipitated crystals were filtered, dried at 60 ° C. for 40 hours, and 9 g of almost colorless crystals were obtained.

Melting Point 168 ~ 171 ℃

This gave the X-ray diffraction diagram as shown in FIG.

Example 20

[Preparation of Form II-a Crystals from Form II-b Crystals]

The crystals of the present invention were prepared according to the method described in Example 19 except that n-heptanol was used instead of n-butanol in Example 19.

Melting Point 168 ~ 171 ℃

This gave the X-ray diffractogram as shown in FIG.

Example 21

[Preparation of Form II-a Crystals from Form II-b Crystals]

The crystals of the present invention were prepared according to the method described in Example 19 except that n-nonanol was used instead of n-butanol in Example 19.

Melting Point 168 ~ 171 ℃

This gave the X-ray diffractogram as shown in FIG.

Example 22

[Preparation of Form II-a Crystals from Form II-b Crystals]

Crystals were prepared in accordance with the method described in Example 19 except that n-undecanol was used instead of n-butanol in Example 19.

Melting Point 168 ~ 171 ℃

This gave the X-ray diffractogram as shown in FIG.

Example 23

[Preparation of Form II-a Crystals from Form II-b Crystals]

Crystals were prepared according to the method described in Example 19 except that n-dodecanol was used instead of n-butanol in Example 19.

Melting Point 168 ~ 171 ℃

This gave the X-ray diffractogram as shown in FIG.

Example 24

[Preparation of Thermal Recording Paper Using Form I-a Crystal of the Present Invention]

A mixture of 10 g of Form I-a crystals of the present invention, 5 g of 10% polyvinyl alcohol aqueous solution and 37.5 g of water is granulated with a sand mill to a particle size of 1.5 mu.

On the other hand, bisphenol A is uniformly dispersed to obtain a 38% developer dispersion. 65.8 g of this color dispersion, 50 g of the aqueous dispersion of the crystal, 18.3 g of 60% hard calcium carbonate aqueous solution, 88 g of 10% polyvinyl alcohol aqueous solution, and 51.9 g of water are mixed.

After applying the mixed solution to wire white No. 10 using a wire rod No. 10, it is dried by wind at room temperature to obtain a very white thermal recording paper which is free of background contamination. The thermal recording paper develops a very reddish black very quickly by heating.

The thermal recording paper was used to measure the color concentration characteristics with respect to temperature using a roddy aceta. The results are shown in FIG. In addition, color development concentration is measured using a film | membrane reflectometer (TR-524 type). The larger the value, the darker the color.

Reference Example 8

[Preparation of Thermal Recording Paper Using the Form I-b Crystal of Public Notice]

A thermosensitive recording paper was produced according to the method described in Example 24 except that a well-known type I-b crystal was used instead of the type I-a crystal of the present invention in Example 24.

Using this thermal recording paper, Rhodi Aceta, color development concentration characteristics with respect to temperature were measured. The results are shown in FIG.

Example 25

[Preparation of Decompression Record Paper Using Form I-a Crystal of the Present Invention]

Preparation of commercial (CB) paper and recycled paper (CF) paper is produced as follows. That is, phenylxylylethane (Nippon) in which 100 g of 10% aqueous solution of ethylene-maleic anhydride copolymer and 240 g of water are mixed and pH 4.0 is dissolved in 10% aqueous sodium hydroxide solution, and 5% by weight of the crystal of form I-a of the present invention is dissolved. 200 g of petrochemical SAS-296) was mixed, emulsified with a homomixer, and 60 g of methylol melamine aqueous solution (Euramin T-30, manufactured by Mitsui Tooatsu Chemical Co., Ltd.) with a solid content of 50% was added to the solution and stirred at 55 ° C. It is kept for 3 hours to obtain a microcapsule dispersion having an average particle diameter of 5.0 mu.

To 100 g of this microcapsule dispersion, 4.0 g of wheat starch granules, 20 g of 20% starch oxide paste and 116 g of water are added and dispersed, and coated on a 40 g / m 2 basis paper so that the coating amount is 5 g / m 2 as a solid content to obtain CB paper.

On the other hand, CF paper uses zinc salts of co-condensation resins of substituted salicylic acid and styrene as the developer, and is refined with a sand grinding mill in water in the presence of a small amount of polymeric anionic surfactant to obtain an aqueous dispersion having a solid content of 40% by weight. Using this aqueous dispersion, an aqueous coating material (solid content 30%) of the following composition was prepared and coated on a good quality paper having a basis weight of 40 g / m 2 so as to have a dry coating amount of 5.5 g / m 2, thereby producing CF paper.

Composition Solid Weight of Water-Based Paint (g)

Hard Calcium Carbonate 100

Prefecture color number 20

Binder Starch Oxide 8

Synthetic Latex 8

When the microcapsule coated surface of CB paper and the developer coated surface of CF paper were polymerized so as to face each other, writing and pressing were carried out, and a reddish black color was obtained on the developer coated surface. Light resistance, moisture resistance, and NOx resistance of this color development are practically not a problem.

Example 26

[Preparation of Thermal Recording Paper Using Type II-a Crystal of the Present Invention]

A mixture of 10 g of the II-a crystal of the present invention, 5 g of 10% polyvinyl alcohol aqueous solution and 37.5 g of water was atomized with a sand mill to a particle size of 1.5 mu.

On the other hand, bisphenol A is uniformly dispersed to obtain a 38% developer dispersion. 65.8 g of this developer dispersion, 50 g of the aqueous dispersion of the above crystals, 18.3 g of a 60% hard calcium carbonate aqueous dispersion, 88 g of a 10% polyvinyl alcohol aqueous solution, and 51.9 g of water are mixed.

The mixed solution is applied to a white paper using Wirerod No. 10, and after application, is dried by wind at room temperature to obtain a very white thermal recording paper free from contamination of the backing paper. The thermal recording paper develops a very reddish black very quickly by heating.

When the uncolored portion of the thermal recording paper was irradiated with sunlight for 3 hours, no yellowing occurred and the whiteness was maintained high (Table 2).

Reference Example 9

[Preparation of Thermal Recording Paper Using Known Type II-b Crystals]

In Example 26, a thermal recording paper was produced in accordance with the method described in Example 26, except that type II-b crystals were used instead of type II-a crystals.

The uncolored portion of the thermal recording paper was irradiated with sunlight for 3 hours, and yellowed (Table 2).

Example 27

[Preparation of Decompression Record Paper Using Type II-a Crystal of the Present Invention]

Preparation of commercial (CB) paper and paper (CF) paper was produced as follows.

In other words, 100 g of 10% aqueous solution of ethylene-maleic anhydride copolymer and 240 g of water were mixed, and phenylxylylethane obtained by dissolving the II-a type crystal of the present invention in 5% by weight with 10% aqueous sodium hydroxide solution ( Nippon Petrochemical SAS-296) 200g was mixed, emulsified with a homomixer, and 60g of dimethylol melamine aqueous solution (Mitsuido Oatsu Chemical Co., Ltd. Yuramin T-30) with a solid content of 50% was added and stirred, It keeps at 55 degreeC for 3 hours, and obtains the microcapsule dispersion liquid with an average particle diameter of 5.0 micrometers.

To 100 g of this microcapsule dispersion, 4.0 g of wheat starch infusion, 20 g of 20% starch oxide paste, and 116 g of water are added to disperse, and coated on paper having a basis weight of 40 g / m 2 so that the coating amount is 5 g / m 2 as a solid content to obtain CB paper.

On the other hand, CF paper uses zinc salts of copolymerized resins of substituted salicylic acid and styrene as the developer, and is refined by sand grinding in water in the presence of a small amount of polymer anionic surfactant to obtain an aqueous dispersion having a solid content of 40% by weight. Using this aqueous dispersion, an aqueous coating material (solid content 30%) having the following composition is prepared, and applied to a good quality paper having a basis weight of 40 g / m 2 so as to have a dry coating amount of 5.5 g / m 2, to prepare CF paper.

Composition Solid Weight of Water-Based Paint (g)

Hard Calcium Carbonate 100

Prefecture color number 20

Binder Starch Oxide 8

Synthetic Latex 8

When the microcapsule coated surface of CB paper and the developer coated surface of CF paper were polymerized so as to face each other, writing and pressing were carried out, and a reddish black color was obtained on the developer coated surface. Light resistance, moisture resistance, and NOx resistance of this color development are practically not a problem.

Claims (12)

In the X-ray diffraction method using Cu-Kα rays, X-ray diffractograms show strong peaks at diffraction angles (2θ) of 7.5 ° and 17.0 °, and relatively strong peaks at 15.1 °, 19.1 °, 21.5 °, and 25.3 °. Crystal of the fluorane compound represented by Formula (I) characterized. In the X-ray diffraction method using Cu-Kα rays, the crystal of the fluorane compound represented by formula (II) characterized by the X-ray diffractogram showing a strong peak at diffraction angles (2θ) of 5.5 ° and 19.2 °. Containing the fluorane compound represented by formula (I), A method for producing a crystal of a fluorane compound according to claim 1, wherein the compound is isolated after the compound is precipitated as a crystal in a solution of an organic solvent containing 30% by weight or more of an aromatic hydrocarbon solvent. A solution of an organic solvent containing at least 30% by weight of an aromatic hydrocarbon solvent containing a fluorane compound is a compound of formula (III) with a compound of formula (IV). (Wherein R represents a lower alkyl group having 1 to 4 carbon atoms) After the dehydration condensation reaction, alkali treatment is carried out in the presence of this organic solvent, and the obtained solvent is a method for producing a crystal of the fluorane compound according to claim 3. In the X-ray diffraction method using Cu-Kα rays, X-ray diffraction diagrams showing strong peaks at diffraction angles (2θ) of 8.7 ° and 14.7 ° and strong peaks at 15.7 °, 19.1 °, 20.1 °, 21.4 °, and 22.9 ° Crystals of the fluorane compound represented by formula (I) characterized by A method for producing a crystal of the fluorane compound according to claim 1, which is dissolved in an organic solvent containing 30% by weight or more of an aromatic hydrocarbon solvent, precipitated as a crystal, and then isolated. The fluorane according to any one of claims 3 to 5, wherein the aromatic hydrocarbon solvent is at least one solvent selected from the group consisting of benzene, toluene, xylene, ethylbenzene, chlorobenzene and dichloro benzene. Method for preparing the crystal of the compound. Containing a fluorane compound represented by formula (II) A method for producing a crystal of the fluorane compound according to claim 2, wherein the compound is precipitated as a crystal in a solution of an organic solvent containing at least 50% by weight of an alcoholic solvent having 3 to 18 carbon atoms. In the X-ray diffraction method using Cu-Kα rays, the formula (II) characterized by the X-ray diffractogram showing strong peaks at diffraction angles (2θ) of 7.7 °, 13.1 °, 17.4 °, 20.3 ° and 20.5 °. Crystal of the fluorane compound represented by, A method for producing a crystal of the fluorane compound according to claim 2, which is dissolved in an organic solvent containing at least 50% by weight of an alcoholic solvent having 3 to 18 carbon atoms, precipitated as a crystal, and then isolated. The method for producing a crystal of a fluorane compound according to claim 7 or 8, wherein the alcohol solvent is an aliphatic alcohol solvent. 10. The solvent according to claim 9, wherein the aliphatic alcohol solvent is at least one solvent selected from the group consisting of propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol and dodecanol. Method for producing a crystal of the fluorane compound, characterized in that. A recording material containing the crystal of the fluorane compound according to claim 1 or 2. 12. The recording material as claimed in claim 11, wherein the recording material is a reduced pressure recording material or a thermosensitive recording material.